Diet and seasonal dispersal of extralimital giraffe at Sanbona Wildlife Reserve, Little Karoo, South Africa

Winter sent these giraffes searching beyond their favourite trees. At Sanbona Wildlife Reserve in South Africa’s Little Karoo, sweet thorn supplied much of their food. But when frost and leaf loss reduced that resource, other trees—and the places where they grew—became important.

Claire Gordon, Liesl Eichenberger and colleagues watched the reserve’s introduced South African giraffes across four seasons in 2014. They recorded feeding at two-minute intervals and identified the plants consumed, drawing on a population of 28 animals. To examine seasonal distribution, they separately mapped guides’ giraffe sightings collected between 2009 and 2013.

The giraffes ate 17 plant species. Sweet thorn dominated feeding overall and was the most-used species in autumn and spring, but karoo boer-bean took first place in winter. Winter sightings also extended more into smaller tributaries where alternative food trees occurred. Because feeding observations and sighting maps came from different years, they do not trace individual animals switching food and moving. Together, however, they reveal the same seasonal problem: a reserve suitable for giraffes when their favourite trees are leafy may need a very different food supply when those leaves disappear.